Fatal error: Uncaught Error: Class "yii\bootstrap4\Alert" not found in /users/quirl/www/filemanager/spark/protected/vendor/kartik-v/yii2-widget-alert/src/Bs4Alert.php:21 Stack trace: #0 {main} thrown in /users/quirl/www/filemanager/spark/protected/vendor/kartik-v/yii2-widget-alert/src/Bs4Alert.php on line 21